This section provides background information related to the present disclosure which is not necessarily prior art. This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
Various arrangements are known in the art for securing the inner bearing ring of a bearing assembly onto a rotating shaft. Such arrangements have included shaft engaging set screws and shaft-surrounding locking collars. Such locking collars include locking or tightening means, generally in the form of one or more locking screws. In the arrangement disclosed in U.S. Pat. Nos. 4,537,519 and 6,908,230, which are hereby incorporated herein and made a part of the present teachings, a bearing assembly is provided wherein the inner ring includes equally spaced inner ring finger extensions or tangs which, when locked with a single screw locking collar, serves to grip and hold a shaft and the inner ring tightly in position allowing improved concentricity of the inner ring with the shaft and higher shaft speeds.
The present teachings can be utilized in combination with any one of a number of known force applying arrangements for securing a bearing assembly to a shaft and are particularly adaptable to the compressible collar and inner ring finger extensions of the known SKWEZLOC® arrangement resulting in the aforementioned advantages of improved shaft-ring concentricity and increased capacity for locking under high loads and high speed shaft operations.
Generally, these bearing assemblies are provided for use with a shaft that passes through the bearing assembly. Specifically, the bearing assembly may include an annular inner ring having a grooved raceway which is wear hardened to extend the bearing life. Surrounding the annular inner ring in spaced relation therefrom, is an annular outer ring having a grooved raceway disposed therein in opposed relationship to the inner ring raceway. The raceways serve to receive in nesting relationship therewith a plurality of spaced ball or rolling elements mounted in rolling element pockets of a rolling element cage. A lubricating passage is provided in the outer bearing ring which is aligned with a passage in bearing assembly housing or pillow block in which bearing assembly is mounted. To seal the rolling element cage assembly, annular inner flingers and outer flingers with annular seals therebetween are press-fitted respectively on the outer and inner bearing rings on either side of the loaded rolling element cage. In this way, the rolling elements can provide reduced frictional rotation of the shaft relative to the bearing assembly while rotating in the hardened raceways of the inner and outer rings.
The inner ring may include the aforementioned inner ring finger extensions or tangs that project from the inner ring and surround the shaft. These finger extensions or tangs are then collapsed to some extent around the shaft to define the concentricity of the now-combined assembly.
However, through recent analysis, it has been found that in some applications where shafts of commercial grade are used, which may lack the turned ground and polished finish of a higher grade shaft, may result in an out of concentricity of the combined inner ring and shaft assembly. That is, use of lower grade shafts having reduced tolerance demand may require that the inner ring finger extensions or tangs accommodate a greater degree of deflection and/or require that the inner ring finger extensions or tangs accommodate a varying degree of deflection from one extension to another extension. However, it has been found that as a result, at least in part, of this greater degree of deflection and the varying degree of deflection from one extension to another extension, the bearing raceway can become distorted upon installation of the locking collar. This can further lead to inconsistent raceway dimensioning between the inner ring and the outer ring causing reduced bearing performance and lifespan.
The present teachings provide an improved inner ring configuration of a bearing assembly capable of accommodating a greater degree of shaft variations and further inhibit raceway deformation. Moreover, the present teachings provide an improved inner ring configuration that is be easily manufactured to provide the benefits of improved concentricity to a greater range of shaft dimensions and conditions. Moreover, the present teachings provide an inner ring configuration that is capable of reducing ball path deformation of the bearing raceway for improved operation and wear.
Accordingly, a bearing assembly for rotatably supporting a shaft member having advantageous construction is provided according to the principles of the present teachings. The bearing assembly includes an outer ring, having a first bearing raceway, and an inner ring, having a second bearing raceway. The raceways are opposingly spaced relative to each other. The inner ring includes a plurality of tang members extending in a cantilevered configuration from at least one end of the inner ring having slots formed therebetween. Bearing members are positioned in a space between and in engagement with the first and second bearing raceways. An undercut groove extends circumferentially along an inner surface of the inner ring generally adjacent the plurality of tang members. The undercut groove is operable to increase an effective cantilever distance of the plurality of tang members. The assembly further includes a locking member engaging the plurality of tang members and exerting a compressing force upon the plurality of tang members to couple the inner ring to the shaft.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.